Personal care compositions for sustained released fragrance delivery are known in the art. Conventional sustained release fragrance delivery systems typically utilize particles containing a pre-encapsulated fragrance to provide for sustained-released delivery of the fragrance. Conventional pre-encapsulated fragrance particles are produced by combining carrier particles (typically starch) and a fragrance in an aqueous medium and spray-drying the mixture at high temperatures (e.g., from about 132° C. to about 204° C.).
The conventional spray drying technique is believed to be necessary for incorporating the fragrance into the carrier material sufficiently to promote gradual release of the fragrance over time. The resulting spray-dried product is then combined with a propellant and other ingredients, and stored in a pressurized container with a release valve (e.g., a spray nozzle) allowing the end user to deliver the composition as an aerosol.
While the conventional pre-encapsulation process is thought to adequately provide a time-released fragrance delivery system, there are disadvantages. For instance, the spray-drying process is not only expensive, but also requires the use of water and high temperatures. The aqueous spray drying process may degrade or reduce the effectiveness of fragrance compositions that are sensitive to such conditions, e.g., fragrances with one or more components that are volatile, thermally sensitive, or unstable in a hot aqueous environment. Fragrances derived from natural sources, e.g., plant extracts, are especially vulnerable. In this regard, the conventional pre-encapsulation process can degrade or eliminate one or more desirable fragrance “notes” that otherwise would have been present in the underlying fragrance.
Conventional pre-encapsulated fragrance products also have inherent problems associated with clogging, making it difficult to consistently and reliably deliver the product as an aerosol. Accordingly, there is a need for a sustained release fragrance delivery product and a method of producing a sustained release fragrance delivery product that overcomes the disadvantages associated with conventional pre-encapsulated fragrance systems.
The invention provides such a product and method. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.